He and other survivors of a 1964 army attack on a peasant community escaped to the mountains and formed Farc, which grew over the decades to include a reputed 15,000 fighters.

Marulanda's deadly aim in combat against the army earned him the name "Sureshot".

Famously reclusive, he is said to have never set foot in Colombia's capital, giving just a handful of interviews over the course of his life.

Farc has suffered a number of blows this year, including the killing of its chief spokesman, Paul Reyes, a senior commander, and the defection of a highly regarded female leader in the group.

Potent force

In recent years, Farc has been driven into remote jungle and mountain areas, but remains a potent force in some areas, bolstered by funds earned from cocaine smuggling.

Backed by billions in US military aid, the government of Alvaro Uribe, the Colombian president, has sent troops to retake areas once under Farc's control.

Attempts to negotiate the release of hostages held by Farc, including French-Colombian politician Ingrid Betancourt and three Americans, are deadlocked over demands made by Farc that Uribe demilitarise a rural zone for negotiations.